Research in Brightshore is very sparse with regards to the subterranean brothers of surface elves1. However, as a former resident of the Underdark, I will write a introductory primer on the topic using my extensive, first-hand knowledge, research from other Brightshore citizens, and obvious2 conjectures on the above-listed sources.
There are primarily two types of Drow in the known world. The Drow under Vessar refer to themselves Chosen3 Drow, where the Drow under Brightshore refer to themselves as the Sanko Drow. Although there are numerous topics on the Chosen Drown, this will narrow itself merely to the Sanko Drow to further expand the research of this interesting culture.
Although the Sanko speak a language very similar to the Chosen Drow's Undercommon, it is distinct enough from the source language to make cross-language understanding difficult. I have elected to refer to it as Sankian, as no Drow has made themselves available to discuss it further.
It is customary to use only last names and apply an honorific. Those without an honoriffic would be addressed as -sa, where those where one would be available should use them. For instance, you could refer to be as Boulderheart-sa, but Boulderheart-wu or even Boulderheart-sensei if referring to the Arcanum.
Speaking to superiors should not be direct, but heavily flourished language. It's considered rude to say “no” in Sankian, but not impolite to say “Nnn” or “What about” instead.
1 Some elves haven taken offense1-2 to this usage, however, the histories indicate that there is a biological similarity between Drow and non-Drow elves.
1-2 Please stop angrily accosting me on the streets. It's not very polite to do to impartial researchers.
2 Some of the conclusions may escape those not invested in research. Please come to a class in the Arcanum if you have further, specific needs to learn.
3 Most documents use the incorrect spelling of Choson. This has been corrected in these records.
4 If a Drow ever asked for admittance to the Arcanum, they would need to be a Wu.